| Hytec Electronics Ltd. |
SPECIFICATION
Basic Features
This is a microprocessor-based bench or rack mounting unit containing two knobs connected to 256-step shaft encoders, a back-lit 8-line, 40 character, liquid-crystal display and two banks of eight push-button switches and associated LEDs. The unit has been designed to provide physical control of computer variables in a most flexible but easy way, and its firmware enables the outputs from the shaft encoders (via an internal 32-bit up/down counter) and switches to be read every 10msec, and if any have changed, passed to the computer by Ethernet or serial link. The firmware allows counters to be preloaded, LEDs to be switched on or off, an alarm to be sounded or the display to be written. This last has a number of possibilities, so that it can be divided into two sections, characters or lines written or deleted, or generally used in any required way. The push-buttons may be used for anything from sensitivity control of the knobs to redirecting the knob to a different variable.
Software
The unit is supplied with a comprehensive and easy to use software package and all the necessary documents and manuals. There are a number of functions built into the unit to facilitate its use in a wide variety of applications, again configurable by software.
Display Functions
There is a wide range of functions available with the Knob Unit, all accessible via the ports. These functions are activated by sending a header byte, followed by the required data. Most of the functions are associated with the display, enabling it to be configured and written to.
Other Functions
There is a parity check on all the data, byte by byte. There is also an optional check sum option, data block by data block. The flexibility of the system enables it to be used for any number of applications in conjunction with a host computer and suitable software to access via the ports.
Mechanical size
[2U X 19" x 12" deep
approximately].
Front Panel
Rear Panel
Other Features
The four potentiometer controls
mentioned above for brightness/volume etc. are normally provided
by a miniature potentiometer and knob. Optionally, they may be
supplied as PCB mounted presets with screwdriver access through
the front panel for adjustment. Internal switches and jumpers
will provide power-on set-up information to the processor
regarding its Ethernet address and Serial Communications
Protocols and Settings.
Internal Construction
The electronics are principally on one
large PCB, with I/O connections along the rear edge as described
above, and cabling connectors along the front edge for connection
to the front panel items. Each front panel ‘section’
has its own cable, i.e. one for each knob encoder, one for each
switch bank, and one each for the LCD display and its backlight
system. The power supply is a separate internal universal input
(90-250VAC) switch-mode unit cabled to the main board.
Processor Section
The ‘engine’ is a Motorola
68HC000 processor with a National Semiconductor SONIC Ethernet
chip, plus other peripherals, all selected for low power
consumption. The processor section uses 128K of EPROM, 256K of
static RAM, all battery-backed, and two complex PLDs for optical
encoder input signals (from the knobs) to provide 32 bits of
up/down counting. All interconnections between boards and panels
are made by keyed plugs and sockets, making assembly and
re-packaging easy.
LCD Display
This is a new type (123mm x 33mm) with
higher contrast display [contrast ratio 20:1, white-on-black]
with high intensity backlight, providing a good angle of view.
Firmware
To the outside world, communicating
with this device through either Ethernet or Serial connection,
this unit will appear exactly the same as the unit which it
replaces, leading to no changes in Host Software.
Options